The present invention relates to an imaging and treatment head for imaging and treating organs or tissues of living beings, and usable in particular for treating various tumors, such as tumors of the thyroid, breast, or uterus. The present invention consequently relates to the field of therapy devices, and more particularly to therapy devices for performing therapy with ultrasound monitoring, and more particularly to therapy devices using power ultrasound. Treatment using focused power ultrasound is known under the acronym HIFU (High Intensity Focused Ultrasound).
The treatment and imaging head of the invention is for mounting on an arm provided with motors, so as to be able to displace the head accurately in various directions. The head is also connected to an electronic control and treatment cabinet, and to a scanner, e.g. an ultrasonic scanner. In addition, the head is generally connected to a cooling unit that causes a refrigerated propagation medium to circulate inside the head. This is a relatively conventional design for an ultrasonic treatment and imaging head using HIFU treatment and an ultrasonic imaging probe, for example. This is only one particular type of treatment device: naturally, other types of treatment device exist that use other imaging and treatment techniques, but without going beyond the ambit of the invention.
The treatment performed by the treatment means of the head may use optionally-focused ultrasound. Amongst treatments using focused ultrasound, treatment using HIFU is already known. The invention preferably, but not exclusively, uses that type of HIFU treatment. Other types of treatment can be used in the ambit of the present invention, and in particular any treatment using waves or radiation that is likely to reach a target that is situated in an organ or a tissue of a living being. The treatment of the present invention is preferably non-invasive: however, invasive treatment can also be envisaged in the ambit of the present invention.
In addition to its treatment means, the imaging and treatment head also includes imaging means that may be of any kind, such as imaging using an ultrasonic probe, an X-ray probe, or IRM, for example. However, imaging using ultrasound is preferred in the ambit of the present invention.
There already exist such imaging and treatment heads that make it possible, in a single unit, to combine the treatment means and the imaging means necessary for locating and showing the target for treatment. It is essential to locate the target for treatment properly, so as to avoid damaging healthy portions of the tissue or of the organ for treatment. To do this, the imaging means must deliver a reliable and accurate representation of the site of the target.
To enable the target for treatment to be located accurately, it is essential for the treatment means and the imaging means to be mutually positioned relative to each other in completely accurate manner. Initially, it is possible to put the imaging means into place, so that they can take an accurate image of the site for treatment. The imaging means may then be moved away and the treatment means are then put into place and positioned very accurately in order to correspond with the image taken by the imaging means. Another technique is to couple the imaging means and the treatment means mechanically on a single head at precise locations. The imaging means, e.g. an ultrasonic probe, are mounted on the head and fastened into place by adhesive. The imaging means are thus integrated in the head.
In particular, it is important that the imaging means and the treatment means have a focal point that coincides where the target is to be placed. Given that the imaging means and the treatment means are both placed in the head, they share a restricted space, and it can thus be said that the imaging means degrade the quality or the performance of the treatment means, and vice versa that the treatment means degrade or reduce the quality of the imaging means. It is thus necessary to find a compromise so as to have an image of sufficient quality for it to be usable, and treatment of sufficiently high performance for it to be able to treat the target correctly.
An object of the present invention is to propose a particularly advantageous configuration for the imaging means and for the treatment means, making it possible to obtain an image of quality that is as high as possible and treatment that is as effective as possible. Another object is for the focal point to be located precisely.
To achieve this object, the present invention proposes a head having imaging means that subdivide the treatment means, substantially in a mid-plane, into two substantially symmetrically identical portions about the imaging means. The symmetry is preferably mirror symmetry about the imaging means. The head advantageously comprises a mounting body on which the imaging and treatment means are mounted, said imaging means comprising a ultrasonic probe having a linear array, the body forming an elongate window, the linear array being positioned so as to emit through the window, the treatment means being positioned on either side of the elongate window. The imaging means thus occupy a minimum amount of space, for maximum quality, while preserving perfect symmetry for the treatment means.
According to another advantageous characteristic of the invention, the head includes a propagation space containing a propagation medium that is suitable for transmitting the waves or radiation emitted by the imaging means and/or the treatment means, the propagation medium penetrating into the space via an inlet and being evacuated from the space via an outlet, said outlet being situated in the proximity of the imaging means. Thus, any risk of bubbles accumulating at the imaging means is avoided. The bubbles tend to form a web in front of the emitter/receiver face of the imaging means, and said web of bubbles deteriorates the quality of the image taken by the imaging means. Evacuating the air bubbles in the direct proximity of the emitter face ensures that no web of bubbles is formed between the emitter/receiver face and the propagation medium. The body advantageously forms a window, the imaging means including an emitter face positioned in the window so as to emit through the propagation medium, the outlet being formed at the window. The outlet advantageously extends in the form of an evacuation channel formed by the body, said channel including a radial section. Advantageously, the channel also includes an axial section that extends substantially perpendicularly to the radial section. The body preferably forms a mounting housing for the imaging means, the window putting the housing into communication with the propagation space, the evacuation channel extending from the window into the body along the housing. The evacuation channel may be constituted merely by a radial section, such that it passes radially through the body of the head so as to open out to the outer periphery of the body. In a variant, it may also include an axial section that extends upwards in register with the radial section and that consequently opens out at the top of the body.
According to another advantageous characteristic of the invention, the imaging means are positioned in the mounting housing by means of an adapter, the outlet being situated in the proximity of the adapter.
In another advantageous aspect of the invention, in use, the imaging means are situated above the treatment means, the imaging means being positioned in the top portion of the window. Thus, the air bubbles that tend to rise in the propagation medium as a result of gravity, would collect in the top portion of the window, but this is avoided as a result of them being evacuated directly out of the propagation space via the outlet situated in the direct proximity of the imaging means.
The position of the outlet in the proximity of the imaging means is a characteristic that may be implemented independently as a result of the imaging means subdividing the treatment means, substantially in a mid-plane, into two portions. This characteristic may be implemented in any imaging and treatment head in which the imaging means are situated above the treatment means, and preferably in the top portion of the propagation space.